The current invention relates to a continuously variable transmission.
Such a transmission is generally known, e.g. by EP-A-0.736.704. In the known construction the transmission is assembled from separable components including a primary pulley, a secondary pulley and a belt. Assembling a transmission with pre-settings assuring a correct alignment at a continuously variable transmission as e.g. described in EP-A-0.291.129, and as required for an optimal operation of the transmission, appears to be relatively difficult in common automotive assembly lines. This on the one hand is due to the assembly speed required and the precise mounting and individual calibration required for each transmission on the other hand.
It is an aim of the current invention to enhance assembly and commercialisation of continuously variable transmissions.
With a construction according to the invention, a belt/pulley assembly may be achieved which may be easily mounted in a transmission structure without compromising the quality of the belt/pulley assembly, and which may be assembled separately by dedicated equipment and personnel.
In a particularly favourable embodiment such assembly is provided with a circumferentially surrounding means fixed to the common support plate for the pulleys. In this way the axial building length may be kept minimal whereas freedom of mounting of elements functional for the operation of the belt/pulley assembly is maintained. The surrounding means protect the belt and pulley grooves from being easily damaged at mounting and during handling. A particular effective protection is achieved when the means extend over the axial positions of the belt. In a preferred embodiment the means are embodied by plate material more in particular synthetic plate material mounted to the supporting plate in a clipped (clamped) manner, so that an effective protection is achieved against in between falling parts like nuts, washers and contamination, while a light weight construction is maintained and while simultaneously an effective oil guiding means, easily adaptable in shape for each application is realised.
A further aspect of the invention reveals that the transmission and it""s apparent method of assembly allows the application of a specific housing according to yet a further aspect of the invention showing a major part, solely completed by a lid part. Such a housing obviates internal hydraulic lines necessarily passing housing sections as commonly applied in known transmission assemblies, thereby obviating the necessity to apply hydraulic sealing means and minimising the risk of leakage and minimising the required amount of maintenance.
For instance in above connection a favourable embodiment of a transmission is thus attained if the assembly also carries a gear for meshing with an input gear as may be required by the application. The support plate is according to the invention favourably provided with an opening for carrying or receiving an intermediary shaft.
The support plate according to the invention may be produced as a housing part, preferably the lid part. In a specific embodiment as preferred according to the invention, the support plate is produced for being inserted into a transmission housing. According to the invention, the housing is produced with support means for receiving the support plate. In particular at least one such so called support means is provided as a so called a self loosing casting or plastic deformation rim, at least partly extending mainly parallel to the predominant direction of extension of the support plate, and transverse to the local housing walls.